1. Field of the Invention
The invention relates to a seat device, more particularly to a seat device for a chair.
2. Description of the Related Art
Referring to FIGS. 1 and 2, a conventional seat cushion 11, 11′ for a chair assembly 1, 1′ is generally supported by a leg assembly 12, 12′. The seat cushion 11 shown in FIG. 1 is made by covering a cotton layer 111 with a synthetic leather 112, thereby providing comfort to a user. The seat cushion 11′ shown in FIG. 2 is made by molding a fabric sheet into a bowl-shaped fabric cushion 113, which corresponds to the sitting posture of a user. The fabric cushion 113 is then mounted detachably on a main frame 13 of a modular chair assembly 1′.
Because the synthetic leather 112 and the cotton layer 111 are easily deformed due to different loads they bear, the conventional seat cushion 11 eventually becomes permanently deformed over time, and therefore becomes uncomfortable to use. As to the fabric cushion 113, since it is made of a non-stretchable fabric material, it cannot match the body shape of each user, and is thus uncomfortable to sit on. Furthermore, since the fabric cushion 113 is not ergonomically sound, the user may suffer body fatigue and pain during long use of the fabric cushion 113, and in the worst case, the pain may be severe and the spinal cord may even be injured.